code: def test_cdt_basic():
      psr = pd.Series(["a", "b", "a", "c"], dtype="category")
      sr = cudf.Series(["a", "b", "a", "c"], dtype="category")
      assert isinstance(sr.dtype, CategoricalDtype)
      assert_eq(sr.dtype.categories, psr.dtype.categories)
  
imports: import numpy
  import pandas
  import pyarrow
  import pytest
  import cudf
  from cudf.core._compat import PANDAS_GE_150
  from cudf.core.column import ColumnBase
  from cudf.core.dtypes import CategoricalDtype, Decimal32Dtype, Decimal64Dtype, Decimal128Dtype, IntervalDtype, ListDtype, StructDtype
  from cudf.testing._utils import assert_eq
  from cudf.utils.dtypes import np_to_pa_dtype
label_desc: Use image node_id 1 for calling a global function with example usage: test_cdt_basic() without return types